The absorption of biologically active materials from the alimentary tract takes place mainly in the intestines.
Many biologically active materials are acid labile, and on exposure to acidic conditions are denatured, or chemically modified such that they lose activity. This presents a problem when the biologically active molecules are orally administered to animals, as for example are many pharmaceutical and veterinary compounds, which need to pass through the stomach.
The stomach region of animals is highly acidic, by virtue of hydrogen ions produced by the parietal cells of the stomach lining. The pH of this region maybe as low a 1 pH unit. Consequently many biological compounds are irreversibly denatured, modified and/or destroyed before they reach the intestinal regions where adsorption takes place.
A number of useful therapeutic compounds and essential minerals are stomach irritants. Particularly, aspirin, Fe.sup.2+, Fe.sup.3+, Zn.sup.2+, K.sup.+, cause stomach irritation when orally administered. This irritation can lead to ulceration of the stomach lining. This disadvantage offsets the therapeutic advantages of these compounds.
Lack or imbalance of digestive enzymes in animals, due to genetic disorders or pancreatic disease, may be treated by the oral administration of enzymes. However, many of these enzymes are acid labile and are irreversibly denatured in the acidic region of the stomach, before they reach the intestinal regions. Consequently, large doses of enzymes have to be given, making this treatment ineffective and expensive.
Biologically active materials are often denatured on passage though the rumen of ruminant animals, where alkaline pH conditions are encountered. This also may act as a barrier to the successful use of orally administered therapeutic agents.
It is an object of the present invention to provide a preparation, and method of delivering biologically active materials to the intestines of animals, the preparation eliminating or substantially reducing the loss of biological activity due to the acidic conditions of the stomach, or the alkaline conditions of the rumen.